Furnace for steam-boilers



(N0 Mudel.) I

R. O. CARPENTER.

. FURNACE FOR STEAM BOILERS.

No. 331,277. Patented Dec. 1, 1885.

UNITED STATES PATENT OFFICE.

ROLLA O. CARPENTER, OF LANSING, MICHIGAN.

FURNACE FOR STEAM-BOILERS.

SPECIFICATION forming part oi Letters Patent No. 331,277, dated December1, 1885. Application filed July 6, 1885. Serial No. 170,828. (No model.)

To all whom it may concern.-

Be it known that I, ROLLA O. CARPENTER, a citizen of the United States,residing at Lansing, in the county of Ingham and State of Michigan, haveinvented a new and useful Improvement in Furnaces for Steam-Boilers, ofwhich the following is a specification.

My invention relates to improvements in furnaces which are adapted tothe use of coal or coke, and the objects of my improvement are tofurnish a supply of air to the unconsumed carbon rising in the form ofsmoke, soot, and gas from the mass of coal, to deflect the mingledcarbons and air from contact with the boiler (which is always at a muchlower temperature than that necessary to produce combustion) until thecombustion of the carbons shall have been perfected, and to produce aperfect combustion of the gases, smoke, and soot. I attain these resultsby the device illustrated in the accompanying drawings, in which Figure1 shows a perpendicular section, and Fig. 2 a horizontal section.

A represents the boiler; B, the outer walls of the furnace. O is abridge-wall, which is built of refractory material, and is built upclose to the boiler, leaving only sufficient space for the expansion ofmaterial. Through this bridge-wall are one or more perforations havingtheir combined area equal to or less than the area of the tubes in theboiler above. The bridge-wall I prefer to build quite thick, so as topresent a large surface at the apertures. The perforations do not extendto the top of the bridge-wall, but a portion of the solid wall is builtabove them for the purpose of deflecting the moving air and combustiblematter from too near an approach to the body of the boiler. Between thebridge-wall and the front of the furnace-wall I place a grate,G, havingan ash-pit below it, as isusual, but so mounted that there is betweenthe front wall of the furnace and the forward end of the grate an openspace (shown at S S) having its area about equal to one-half that of theperforations in the bridge-wall. Therequisites of this opening are, thatit shall not be clogged by throwing coal or combustibles over it, andthat it be constantly kept free for the passage of air; but the openingin whatever form should have an area less than or about equal toone-half the area of the perforations in the bridge-wall, and soconstructed that they shall be kept constantly open and free fromchoking combustibles. A current of air entering through the ordinarydamper-openings in the front of the furnace passes in part through theburning coal upon the grate and in part through the aperture S S infront of the grate, and the latter portion, while passing over the coaltoward and through the openings in the bridge-wall and there minglingwit-h the unconsumed combustible material rising from the coal,furnishes a fresh supply of oxygen, and promotes complete combustion asthe mixed air and combustible material pass through the perforations.The location of the perforations in the wall at a distance below theboiler causes the combustible material to be drawn away from the(comparatively) cool boiler, and prevents the cooling of the gases andtheir consequent failure to burn. The hot gases, with their combustiblematerial completely burned out, pass on their way to the chimney throughthe fiues ff, and there part with their heat tothe water surrounding theflues.

The aperture S S can be utilized by the fireman for the ready removal ofclinkers, and its presence compels the proper admission of air over thetop of the burning coal, in spite of the most careless attention of thefireman.

The grate G may be set either horizontal or raking. I prefer to set itwith the rear end lower, as such a setting causes the coal to constantlywork backward and away from the aperture S S.

Having thus described my invention and its mode of operation, what Iclaim as new, and desire to have secured to me by Letters Patent, is

1. In a furnace for steam-boilers, the combination of a grate, set withan aperture between its forward end and the forward end of thefurnace-wall, and a bridge-wall of refraetory material, perforated,substantially as bined with a grate set so as to leave an apdescribed.erture at the forward end thereof of a less or 2. In a furnace forsteam-boilers, a perfonearly the same area. rated bridge-Wall behind thegrate having ROLLA G. CARPENTER. 5 the perforations, substantially asdescribed, In presence ofof an area jointly about equal to two-thirds J.W. MATTHEWS, the area of the fire-flues in the boiler, corn- LUKE O.COLBURN.

